Spherical bearing assembly with spring biased segmented inner race member

ABSTRACT

A spherical bearing assembly having an inner race member and an outer race member, the inner surface of the outer race member being a concave spherical surface, the outer surface of the inner member being a complementary convex spherical surface, the inner member including a spool member having two annular lips at each end thereof, and at least three spherical segments interlocked by the annular lips in an axial direction on the spool member, a gap provided between at least two of the spherical segments, a spring member interposed between the segments in the area defined by the gaps to axially bias and preload the segments against each other.

BACKGROUND OF THE INVENTION

The present invention relates generally to self-aligning bearings havinga ball-like inner member with a convex outer surface and an outer memberhaving an inner surface with a complementary concave spherical innerface. These types of bearings, which are commonly called "sphericalbearings," have been utilized in industry for a substantial period oftime. The technological evolution of these type bearings has beendirected more in the terms of material composition of its variouscomponent parts rather than toward basic changes in design concepts.Accordingly, the design advances in spherical bearings have not beensubstantial in nature and thereby presently limiting their applications.

One area in which the spherical bearings have been extensively appliedis the aircraft industry. This is due to the spherical bearingself-aligning characteristic. A typical such application is marrying ofa spherical bearing to a landing gear strut or member of an airplane. Inthis application the outer race is commonly press-fitted into a housingor the like rendering it difficult to remove and/or maintain. When anysuch maintenance is required, such as replacing of the ball, the entirebearing assembly including the inner and outer race member would have tobe removed and replaced by an entirely new bearing assembly. Such anoperation could entail substantial expense and down time of the entireaircraft.

There are a number of prior art type spherical bearings which have beenaddressed to this kind of problem. One such type prior art bearing isthe "messerschmidt" bearing. A concept of this bearing is that the ballcan be removed in the field without disassembling the entire bearing,that is, removing the outer race member from its mounting. Themesserschmidt type spherical bearing has proved somewhat unsatisfactoryin that its overall bearing surface is decreased by the provision of aslot. This decrease or rather limited bearing surface area has a markednegative effect on the bearing performance characteristics.

SUMMARY OF THE INVENTION

It is therefore, a primary object of the present invention to provide aspherical bearing assembly having an inner race member and an outer racemember, the inner surface of the outer race member being a concavespherical surface, the outer surface of the inner member being acomplementary convex spherical surface, said inner member including aspool member having two annular lips at each end thereof, and at leastthree spherical segments interlocked by the annular lips in an axialdirection with said spool member, a gap provided between at least two ofsaid spherical segments, spring member interposed between the segmentsin the area defined by the gaps to axially bias and preload the segmentsagainst each other.

It is yet another object of the present invention to provide a sphericalbearing assembly which has a rotational redundancy. That is, the innermember is adapted to be rotatably mounted within the outer member. Afirst bearing surface between these two members being defined by theconvex outer surface of the inner member and the complementary concaveinner surface of the outer member. The rotational redundancy provided bythe spherical bearing of the present invention is the second bearingsurface between the longitudinal inner surface of the segments of theinner member and the cylindrical outer surface of the spool member.

It is still another object of the present invention to provide aspherical bearing assembly in accordance with the present inventionwherein the spool member is provided with annular lips, for example, onelip disposed at each end of the spool member or a lip centrally disposedon the spool member.

It is still another object of the present invention to provide aspherical bearing assembly in accordance with the present inventionwherein the annular lips of the spool member have an outer surface whichis a continuation of the convex spherical surface of the inner member.

It is yet another object of the present invention to provide a sphericalbearing assembly in accordance with the present invention wherein theannular lips on the spool member maintain the segments upon the spoolmember so as to mechanically interlock them thereon when the member isin its operational position.

It is still another object of the present invention to provide aspherical bearing assembly in which the intermediate segments aresmaller in a circumferential dimension than the spherical bearingsegments.

It is still another object of the present invention to provide aspherical bearing assembly in which the spring member is manufactured ina sinusoidal shape with radially projecting undulations.

It is yet another object of the present invention to provide a sphericalbearing assembly in which the springs are manufactured from springsteel.

Embodiments of the bearing according to the concept of the presentinvention are shown and/or described by way of example in theaccompanying drawings and following description of the invention withoutattempting to show or describe all of the various forms andmodifications in which the invention might be embodied; the inventionbeing measured by the appended claims and not by the details of thespecification.

FIG. 1 is a side elevational view of the spherical bearing assemblyembodying the present invention with the longitudinal axis of the outerrace member and the inner race member being substantially coincident;

FIG. 2 is a front sectional view taken along line 2--2 of FIG. 1;

FIG. 3 is a perspective sectional view of the bearing of FIG. 2 with oneof the segments and two of the spring members of the inner race memberremoved;

FIG. 4 is a side elevational view of the spring member in accordancewith the present invention;

FIG. 5 is a top view of the spring member of FIG. 4.

DESCRIPTION OF THE INVENTION

A spherical bearing embodying the concept of the present invention isgenerally indicated, as appropriate, by numeral 10 on the attacheddrawing as set forth in FIGS. 1 through 5, inclusive.

The bearing 10 has been shown as a spherical bearing, however, thepresent invention is also directly applicable to male or female rod endtype bearings and the like.

The spherical bearing 10 comprises an outer member 12 which may beprovided with an outer cylindrical surface 14. The outer member 12 mayalso be provided with two annular faces 16. The outer member 12 isfurther provided with a concave spherical inner surface 18. It may benoted at this juncture that the outer member 12 may be similar to theouter race members as found in the prior art.

The basic thrust of the present invention is to be found in the innerrace member, hereafter referred to as the inner member which istypically formed, in the prior art, as a single solid member. The innermember 20 as distinguished from the inner members of the prior art is acomposite member having several parts. One component part or member isthe spool member 22. The spool member 22 may be characterized as acylindrically shaped spool having two annular lips 24, one at each endthereof. The portion of the lips, of course, can be changed as forexample there could be one centrally disposed lip on the spool member22. The spool member 22 and the annular lips 24, are so sized as to beable to be placed within the surface defined by the concave innersurface 18 of the outer member 12.

The spool member 22 and its various associated parts may be rotated suchthat its longitudinal axis is perpendicular to the longitudinal axis ofthe outer race member 12. When the spool member is rotated in such afashion that the convex outer surface of the inner member 20 is exposedsubstantially all of the convex surface of the inner member which isformed and defined by at least three segments 26. There may be at leastthree equally sized segments 26 on the spool member 22 as well as atleast one spring member 30. The annular lips 24 maintain the positionalintegrity, in an axial direction, of the segments 26 and spring members30 on the spool member 22. However, the segments 26 and the springmembers 30 may be removed from the spool member 22 when the spool memberis rotated in the above-noted fashion. Each segment 26 and the springmembers 30 may be moved in turn from the spool member 22 ultimatelyleaving the spool member completely devoid of the segments 26 and springmembers 30. Thereafter, the spool member can be removed entirely fromthe outer member 12. It can be seen, therefore, that the inner membercan be completely dismantled and removed from the outer member 12without dislodging or otherwise interferring with the position or thecondition of the outer member with respect to its mounting surface (notshown). Therefore the outer face member is fixedly attached to somestructural surface such as by press-fit or the like. For example, in anaircraft type application, a new inner member may be inserted quicklyand efficiently without disturbing any other part of the aircraft exceptthat part which is directly attached to the inner member 20.

A very important feature of the present invention is that the springmembers, which are interposed in gaps between the segments 26 provide anaxial biasing and preloading force bearing on the segments 26. As can beseen in FIGS. 4 and 5 spring members 30 may be of spring steel materialand fashioned in a sinusoidal form with radial projecting undulations.In this manner "internal play" is effected in the bearing assembly whichenables the bearing to accommodate high shock loading without damagingthe various bearing parts.

The spherical bearing 10 inherently embodies a second or redundantbearing surface. In particular, the inner surfaces 28 of the segments 26and intermediate segments 30 and the outer surface 31 of the spoolmember 22 may define a second bearing surface. This bearing surface canbecome particularly important in a situation where there may beinterference between the inner member and the outer member at thebearing surface defined by the concave inner surface of the outer member12 and the convex outer surface of the inner member 20. Upon any suchinterference, which may be caused by corrosion, dirt or the like, theabove-noted second bearing surface between the spherical segments 26 and30 and spool member 22 could then provide for a degree of movement. Thismovement can be further enhanced by the self-lubricating action of theintermediate spherical segments 30 which would lubricate the secondbearing surface.

The annular lips 24 may be so shaped such that their outer surface wouldbe a continuation of the spherical surface of the segments.Additionally, the outer surface of the annular lips may be defined by anumber of other forms such as a chordal section subtending the sphericalsurface defined by the outer surface of the segments 26 and 30.Additionally, the annular lips may be reduced in size to a point wherethey merely maintain the axial position of the segments 26 on the spoolmember 22 but are not involved in any way with the bearing surface areaof the segments 26 and spring members 30.

As before mentioned, the present invention provides a marked improvementin the ability to service spherical bearings in the field withoutdisplacing or otherwise dislodging the outer race member. This isaccomplished without any compromise in the bearing performance orcharacteristic such as a reduction in the overall bearing surface whichis typified by the prior art bearings such as the messerschmidt typeball spherical bearing.

From the above description of the invention along with various figuresas set forth in the drawings it will be readily seen and appreciatedthat a spherical bearing embodying the concept of the present inventionwill positively and effectively accomplish the objectives of theinvention. The above-noted embodiment is shown by way of example withoutattempting to show all the various forms and modifications in which theinvention might be embodied; the invention being measured by theappended claims and not the specific details of the specification.

I claim:
 1. A spherical bearing assembly having an inner race member andan outer race member, the inner surface of the outer race member being aconcave spherical surface, the outer surface of the inner member being acomplementary convex spherical surface, the inner member including aspool member having two annular lips at each end thereof and at leastthree axially segmented spherical segments interlocked by said annularlips in an axial direction on the spool member, the spherical segmentshaving outer curved spherical faces for abutting the inner concavespherical surface of the outer race member and having inner curvedsurfaces for positioning near an outer surface of the spool member, andthe spherical segments having radially extending faces interconnectingthe outer curved spherical faces and the inner curved surfaces, a gapprovided between at least two opposite adjacent radially extending facesof said spherical segments, a spring member segment interposed betweensaid opposite adjacent radially extending faces of said segments in thearea defined by said gap to axially bias and preload said segmentsagainst each other, the spring member extending from the inner curvedsurfaces to the outer curved spherical faces of the spherical segments.2. A spherical bearing assembly in accordance with claim 3 wherein saidspring members are manufactured from spring steel.
 3. A sphericalbearing assembly in accordance with claim 1 wherein said spring membersare formed in a sinusoidal sheet fashion with radially projectingundulations.
 4. A spherical bearing assembly in accordance with claim 3wherein there are three spring members and three segments.